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authorTavian Barnes <tavianator@tavianator.com>2022-11-09 11:14:12 -0500
committerTavian Barnes <tavianator@tavianator.com>2022-11-09 12:08:20 -0500
commitb41dca52762c5188638236ae81b9f4597bb29ac9 (patch)
tree4d503f6dcee1b1ed15ef61df3c8ccb9b92533546 /src
parentdd6808539013061a3113e45c7267430e56749f2c (diff)
downloadbfs-b41dca52762c5188638236ae81b9f4597bb29ac9.tar.xz
pwcache: Fill the user/group caches lazily
Iterating all the users/groups can be expensive, especially with NSS. Android has so many that it doesn't even return them all from get{pw,gr}ent() for performance reasons, leading to incorrect behaviour of -user/-group/etc.
Diffstat (limited to 'src')
-rw-r--r--src/ctx.c50
-rw-r--r--src/ctx.h24
-rw-r--r--src/eval.c25
-rw-r--r--src/opt.c19
-rw-r--r--src/parse.c68
-rw-r--r--src/printf.c30
-rw-r--r--src/pwcache.c322
-rw-r--r--src/pwcache.h52
8 files changed, 226 insertions, 364 deletions
diff --git a/src/ctx.c b/src/ctx.c
index b2f7d56..8d80691 100644
--- a/src/ctx.c
+++ b/src/ctx.c
@@ -84,9 +84,7 @@ struct bfs_ctx *bfs_ctx_new(void) {
ctx->cerr = NULL;
ctx->users = NULL;
- ctx->users_error = 0;
ctx->groups = NULL;
- ctx->groups_error = 0;
ctx->mtab = NULL;
ctx->mtab_error = 0;
@@ -95,45 +93,27 @@ struct bfs_ctx *bfs_ctx_new(void) {
ctx->nfiles = 0;
struct rlimit rl;
- if (getrlimit(RLIMIT_NOFILE, &rl) == 0) {
- ctx->nofile_soft = rl.rlim_cur;
- ctx->nofile_hard = rl.rlim_max;
- } else {
- ctx->nofile_soft = 1024;
- ctx->nofile_hard = RLIM_INFINITY;
+ if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
+ goto fail;
}
+ ctx->nofile_soft = rl.rlim_cur;
+ ctx->nofile_hard = rl.rlim_max;
- return ctx;
-}
-
-const struct bfs_users *bfs_ctx_users(const struct bfs_ctx *ctx) {
- struct bfs_ctx *mut = (struct bfs_ctx *)ctx;
-
- if (mut->users_error) {
- errno = mut->users_error;
- } else if (!mut->users) {
- mut->users = bfs_users_parse();
- if (!mut->users) {
- mut->users_error = errno;
- }
+ ctx->users = bfs_users_new();
+ if (!ctx->users) {
+ goto fail;
}
- return mut->users;
-}
-
-const struct bfs_groups *bfs_ctx_groups(const struct bfs_ctx *ctx) {
- struct bfs_ctx *mut = (struct bfs_ctx *)ctx;
-
- if (mut->groups_error) {
- errno = mut->groups_error;
- } else if (!mut->groups) {
- mut->groups = bfs_groups_parse();
- if (!mut->groups) {
- mut->groups_error = errno;
- }
+ ctx->groups = bfs_groups_new();
+ if (!ctx->groups) {
+ goto fail;
}
- return mut->groups;
+ return ctx;
+
+fail:
+ bfs_ctx_free(ctx);
+ return NULL;
}
const struct bfs_mtab *bfs_ctx_mtab(const struct bfs_ctx *ctx) {
diff --git a/src/ctx.h b/src/ctx.h
index 6c4ef33..d32db59 100644
--- a/src/ctx.h
+++ b/src/ctx.h
@@ -106,10 +106,8 @@ struct bfs_ctx {
/** Colored stderr. */
struct CFILE *cerr;
- /** User table. */
+ /** User cache. */
struct bfs_users *users;
- /** The error that occurred parsing the user table, if any. */
- int users_error;
/** Group table. */
struct bfs_groups *groups;
/** The error that occurred parsing the group table, if any. */
@@ -138,26 +136,6 @@ struct bfs_ctx {
struct bfs_ctx *bfs_ctx_new(void);
/**
- * Get the users table.
- *
- * @param ctx
- * The bfs context.
- * @return
- * The cached users table, or NULL on failure.
- */
-const struct bfs_users *bfs_ctx_users(const struct bfs_ctx *ctx);
-
-/**
- * Get the groups table.
- *
- * @param ctx
- * The bfs context.
- * @return
- * The cached groups table, or NULL on failure.
- */
-const struct bfs_groups *bfs_ctx_groups(const struct bfs_ctx *ctx);
-
-/**
* Get the mount table.
*
* @param ctx
diff --git a/src/eval.c b/src/eval.c
index dc46a23..f756617 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -309,13 +309,11 @@ bool eval_nogroup(const struct bfs_expr *expr, struct bfs_eval *state) {
return false;
}
- const struct bfs_groups *groups = bfs_ctx_groups(state->ctx);
- if (!groups) {
+ const struct group *grp = bfs_getgrgid(state->ctx->groups, statbuf->gid);
+ if (errno != 0) {
eval_report_error(state);
- return false;
}
-
- return bfs_getgrgid(groups, statbuf->gid) == NULL;
+ return grp == NULL;
}
/**
@@ -327,13 +325,11 @@ bool eval_nouser(const struct bfs_expr *expr, struct bfs_eval *state) {
return false;
}
- const struct bfs_users *users = bfs_ctx_users(state->ctx);
- if (!users) {
+ const struct passwd *pwd = bfs_getpwuid(state->ctx->users, statbuf->uid);
+ if (errno != 0) {
eval_report_error(state);
- return false;
}
-
- return bfs_getpwuid(users, statbuf->uid) == NULL;
+ return pwd == NULL;
}
/**
@@ -642,8 +638,7 @@ bool eval_perm(const struct bfs_expr *expr, struct bfs_eval *state) {
bool eval_fls(const struct bfs_expr *expr, struct bfs_eval *state) {
CFILE *cfile = expr->cfile;
FILE *file = cfile->file;
- const struct bfs_users *users = bfs_ctx_users(state->ctx);
- const struct bfs_groups *groups = bfs_ctx_groups(state->ctx);
+ const struct bfs_ctx *ctx = state->ctx;
const struct BFTW *ftwbuf = state->ftwbuf;
const struct bfs_stat *statbuf = eval_stat(state);
if (!statbuf) {
@@ -651,7 +646,7 @@ bool eval_fls(const struct bfs_expr *expr, struct bfs_eval *state) {
}
uintmax_t ino = statbuf->ino;
- uintmax_t block_size = state->ctx->posixly_correct ? 512 : 1024;
+ uintmax_t block_size = ctx->posixly_correct ? 512 : 1024;
uintmax_t blocks = ((uintmax_t)statbuf->blocks*BFS_STAT_BLKSIZE + block_size - 1)/block_size;
char mode[11];
xstrmode(statbuf->mode, mode);
@@ -662,7 +657,7 @@ bool eval_fls(const struct bfs_expr *expr, struct bfs_eval *state) {
}
uintmax_t uid = statbuf->uid;
- const struct passwd *pwd = users ? bfs_getpwuid(users, uid) : NULL;
+ const struct passwd *pwd = bfs_getpwuid(ctx->users, uid);
if (pwd) {
if (fprintf(file, " %-8s", pwd->pw_name) < 0) {
goto error;
@@ -674,7 +669,7 @@ bool eval_fls(const struct bfs_expr *expr, struct bfs_eval *state) {
}
uintmax_t gid = statbuf->gid;
- const struct group *grp = groups ? bfs_getgrgid(groups, gid) : NULL;
+ const struct group *grp = bfs_getgrgid(ctx->groups, gid);
if (grp) {
if (fprintf(file, " %-8s", grp->gr_name) < 0) {
goto error;
diff --git a/src/opt.c b/src/opt.c
index cece337..fa2e66c 100644
--- a/src/opt.c
+++ b/src/opt.c
@@ -48,6 +48,7 @@
#include "expr.h"
#include "pwcache.h"
#include <assert.h>
+#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdbool.h>
@@ -789,12 +790,13 @@ static void infer_icmp_facts(struct opt_state *state, const struct bfs_expr *exp
static void infer_gid_facts(struct opt_state *state, const struct bfs_expr *expr) {
infer_icmp_facts(state, expr, GID_RANGE);
- const struct bfs_groups *groups = bfs_ctx_groups(state->ctx);
struct range *range = &state->facts_when_true.ranges[GID_RANGE];
- if (groups && range->min == range->max) {
+ if (range->min == range->max) {
gid_t gid = range->min;
- bool nogroup = !bfs_getgrgid(groups, gid);
- constrain_pred(&state->facts_when_true.preds[NOGROUP_PRED], nogroup);
+ bool nogroup = !bfs_getgrgid(state->ctx->groups, gid);
+ if (errno == 0) {
+ constrain_pred(&state->facts_when_true.preds[NOGROUP_PRED], nogroup);
+ }
}
}
@@ -802,12 +804,13 @@ static void infer_gid_facts(struct opt_state *state, const struct bfs_expr *expr
static void infer_uid_facts(struct opt_state *state, const struct bfs_expr *expr) {
infer_icmp_facts(state, expr, UID_RANGE);
- const struct bfs_users *users = bfs_ctx_users(state->ctx);
struct range *range = &state->facts_when_true.ranges[UID_RANGE];
- if (users && range->min == range->max) {
+ if (range->min == range->max) {
uid_t uid = range->min;
- bool nouser = !bfs_getpwuid(users, uid);
- constrain_pred(&state->facts_when_true.preds[NOUSER_PRED], nouser);
+ bool nouser = !bfs_getpwuid(state->ctx->users, uid);
+ if (errno == 0) {
+ constrain_pred(&state->facts_when_true.preds[NOUSER_PRED], nouser);
+ }
}
}
diff --git a/src/parse.c b/src/parse.c
index a4cb4fc..45242f0 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -1526,12 +1526,6 @@ static struct bfs_expr *parse_fls(struct parser_state *state, int arg1, int arg2
expr_set_always_true(expr);
expr->cost = PRINT_COST;
expr->reftime = state->now;
-
- // We'll need these for user/group names, so initialize them now to
- // avoid EMFILE later
- bfs_ctx_users(state->ctx);
- bfs_ctx_groups(state->ctx);
-
return expr;
fail:
@@ -1647,13 +1641,7 @@ static struct bfs_expr *parse_group(struct parser_state *state, int arg1, int ar
return NULL;
}
- const struct bfs_groups *groups = bfs_ctx_groups(state->ctx);
- if (!groups) {
- parse_expr_error(state, expr, "Couldn't parse the group table: %m.\n");
- goto fail;
- }
-
- const struct group *grp = bfs_getgrnam(groups, expr->argv[1]);
+ const struct group *grp = bfs_getgrnam(state->ctx->groups, expr->argv[1]);
if (grp) {
expr->num = grp->gr_gid;
expr->int_cmp = BFS_INT_EQUAL;
@@ -1661,13 +1649,15 @@ static struct bfs_expr *parse_group(struct parser_state *state, int arg1, int ar
if (!parse_icmp(state, expr, 0)) {
goto fail;
}
+ } else if (errno) {
+ parse_expr_error(state, expr, "%m.\n");
+ goto fail;
} else {
parse_expr_error(state, expr, "No such group.\n");
goto fail;
}
expr->cost = STAT_COST;
-
return expr;
fail:
@@ -1703,13 +1693,7 @@ static struct bfs_expr *parse_user(struct parser_state *state, int arg1, int arg
return NULL;
}
- const struct bfs_users *users = bfs_ctx_users(state->ctx);
- if (!users) {
- parse_expr_error(state, expr, "Couldn't parse the user table: %m.\n");
- goto fail;
- }
-
- const struct passwd *pwd = bfs_getpwnam(users, expr->argv[1]);
+ const struct passwd *pwd = bfs_getpwnam(state->ctx->users, expr->argv[1]);
if (pwd) {
expr->num = pwd->pw_uid;
expr->int_cmp = BFS_INT_EQUAL;
@@ -1717,13 +1701,15 @@ static struct bfs_expr *parse_user(struct parser_state *state, int arg1, int arg
if (!parse_icmp(state, expr, 0)) {
goto fail;
}
+ } else if (errno) {
+ parse_expr_error(state, expr, "%m.\n");
+ goto fail;
} else {
parse_expr_error(state, expr, "No such user.\n");
goto fail;
}
expr->cost = STAT_COST;
-
return expr;
fail:
@@ -1785,12 +1771,6 @@ static struct bfs_expr *parse_ls(struct parser_state *state, int arg1, int arg2)
init_print_expr(state, expr);
expr->reftime = state->now;
-
- // We'll need these for user/group names, so initialize them now to
- // avoid EMFILE later
- bfs_ctx_users(state->ctx);
- bfs_ctx_groups(state->ctx);
-
return expr;
}
@@ -2005,16 +1985,18 @@ fail:
* Parse -nogroup.
*/
static struct bfs_expr *parse_nogroup(struct parser_state *state, int arg1, int arg2) {
- if (!bfs_ctx_groups(state->ctx)) {
- parse_error(state, "Couldn't parse the group table: %m.\n");
+ struct bfs_expr *expr = parse_nullary_test(state, eval_nogroup);
+ if (!expr) {
return NULL;
}
- struct bfs_expr *expr = parse_nullary_test(state, eval_nogroup);
- if (expr) {
- expr->cost = STAT_COST;
- expr->probability = 0.01;
- }
+ expr->cost = STAT_COST;
+ expr->probability = 0.01;
+
+ // Who knows how many FDs getgrgid_r() needs? Probably at least one for
+ // /etc/group
+ expr->ephemeral_fds = 1;
+
return expr;
}
@@ -2051,16 +2033,18 @@ static struct bfs_expr *parse_noleaf(struct parser_state *state, int arg1, int a
* Parse -nouser.
*/
static struct bfs_expr *parse_nouser(struct parser_state *state, int arg1, int arg2) {
- if (!bfs_ctx_users(state->ctx)) {
- parse_error(state, "Couldn't parse the user table: %m.\n");
+ struct bfs_expr *expr = parse_nullary_test(state, eval_nouser);
+ if (!expr) {
return NULL;
}
- struct bfs_expr *expr = parse_nullary_test(state, eval_nouser);
- if (expr) {
- expr->cost = STAT_COST;
- expr->probability = 0.01;
- }
+ expr->cost = STAT_COST;
+ expr->probability = 0.01;
+
+ // Who knows how many FDs getpwuid_r() needs? Probably at least one for
+ // /etc/passwd
+ expr->ephemeral_fds = 1;
+
return expr;
}
diff --git a/src/printf.c b/src/printf.c
index 57ff5fd..6a7b9a9 100644
--- a/src/printf.c
+++ b/src/printf.c
@@ -59,7 +59,7 @@ struct bfs_printf {
/** Character data associated with this directive. */
char c;
/** Some data used by the directive. */
- const void *ptr;
+ void *ptr;
};
/** Print some text as-is. */
@@ -259,8 +259,8 @@ static int bfs_printf_g(CFILE *cfile, const struct bfs_printf *directive, const
return -1;
}
- const struct bfs_groups *groups = directive->ptr;
- const struct group *grp = groups ? bfs_getgrgid(groups, statbuf->gid) : NULL;
+ struct bfs_groups *groups = directive->ptr;
+ const struct group *grp = bfs_getgrgid(groups, statbuf->gid);
if (!grp) {
return bfs_printf_G(cfile, directive, ftwbuf);
}
@@ -469,8 +469,8 @@ static int bfs_printf_u(CFILE *cfile, const struct bfs_printf *directive, const
return -1;
}
- const struct bfs_users *users = directive->ptr;
- const struct passwd *pwd = users ? bfs_getpwuid(users, statbuf->uid) : NULL;
+ struct bfs_users *users = directive->ptr;
+ const struct passwd *pwd = bfs_getpwuid(users, statbuf->uid);
if (!pwd) {
return bfs_printf_U(cfile, directive, ftwbuf);
}
@@ -733,24 +733,18 @@ int bfs_printf_parse(const struct bfs_ctx *ctx, struct bfs_expr *expr, const cha
directive.fn = bfs_printf_f;
break;
case 'F':
- directive.ptr = bfs_ctx_mtab(ctx);
+ directive.fn = bfs_printf_F;
+ directive.ptr = (void *)bfs_ctx_mtab(ctx);
if (!directive.ptr) {
int error = errno;
bfs_expr_error(ctx, expr);
bfs_error(ctx, "Couldn't parse the mount table: %s.\n", strerror(error));
goto directive_error;
}
- directive.fn = bfs_printf_F;
break;
case 'g':
- directive.ptr = bfs_ctx_groups(ctx);
- if (!directive.ptr) {
- int error = errno;
- bfs_expr_error(ctx, expr);
- bfs_error(ctx, "Couldn't parse the group table: %s.\n", strerror(error));
- goto directive_error;
- }
directive.fn = bfs_printf_g;
+ directive.ptr = ctx->groups;
break;
case 'G':
directive.fn = bfs_printf_G;
@@ -798,14 +792,8 @@ int bfs_printf_parse(const struct bfs_ctx *ctx, struct bfs_expr *expr, const cha
directive.stat_field = BFS_STAT_MTIME;
break;
case 'u':
- directive.ptr = bfs_ctx_users(ctx);
- if (!directive.ptr) {
- int error = errno;
- bfs_expr_error(ctx, expr);
- bfs_error(ctx, "Couldn't parse the user table: %s.\n", strerror(error));
- goto directive_error;
- }
directive.fn = bfs_printf_u;
+ directive.ptr = ctx->users;
break;
case 'U':
directive.fn = bfs_printf_U;
diff --git a/src/pwcache.c b/src/pwcache.c
index 91435bd..7071f59 100644
--- a/src/pwcache.c
+++ b/src/pwcache.c
@@ -1,6 +1,6 @@
/****************************************************************************
* bfs *
- * Copyright (C) 2020 Tavian Barnes <tavianator@tavianator.com> *
+ * Copyright (C) 2020-2022 Tavian Barnes <tavianator@tavianator.com> *
* *
* Permission to use, copy, modify, and/or distribute this software for any *
* purpose with or without fee is hereby granted. *
@@ -23,270 +23,200 @@
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
+#include <unistd.h>
-struct bfs_users {
- /** The array of passwd entries. */
- struct passwd *entries;
- /** A map from usernames to entries. */
- struct trie by_name;
- /** A map from UIDs to entries. */
- struct trie by_uid;
-};
+/** Represents cache hits for negative results. */
+static void *MISSING = &MISSING;
-struct bfs_users *bfs_users_parse(void) {
- int error;
+/** Callback type for bfs_getent(). */
+typedef void *bfs_getent_fn(const void *key, void *ent, void *buf, size_t bufsize);
- struct bfs_users *users = malloc(sizeof(*users));
- if (!users) {
- return NULL;
+/** Shared scaffolding for get{pw,gr}{nam,?id}_r(). */
+static void *bfs_getent(struct trie_leaf *leaf, bfs_getent_fn *fn, const void *key, size_t entsize, size_t bufsize) {
+ if (leaf->value) {
+ errno = 0;
+ return leaf->value == MISSING ? NULL : leaf->value;
}
- users->entries = NULL;
- trie_init(&users->by_name);
- trie_init(&users->by_uid);
-
- setpwent();
-
+ void *buf = NULL;
while (true) {
- errno = 0;
- struct passwd *ent = getpwent();
- if (!ent) {
- if (errno) {
- error = errno;
- goto fail_end;
- } else {
- break;
- }
- }
-
- if (DARRAY_PUSH(&users->entries, ent) != 0) {
- error = errno;
- goto fail_end;
+ void *result = buf;
+ buf = realloc(buf, entsize + bufsize);
+ if (!buf) {
+ free(result);
+ return NULL;
}
- ent = users->entries + darray_length(users->entries) - 1;
- ent->pw_name = strdup(ent->pw_name);
- ent->pw_dir = strdup(ent->pw_dir);
- ent->pw_shell = strdup(ent->pw_shell);
- if (!ent->pw_name || !ent->pw_dir || !ent->pw_shell) {
- error = ENOMEM;
- goto fail_end;
+ result = fn(key, buf, (char *)buf + entsize, bufsize);
+ if (result) {
+ leaf->value = result;
+ return result;
+ } else if (errno == 0) {
+ free(buf);
+ leaf->value = MISSING;
+ return NULL;
+ } else if (errno == ERANGE) {
+ bufsize *= 2;
+ } else {
+ free(buf);
+ return NULL;
}
}
+}
- endpwent();
+struct bfs_users {
+ /** Initial buffer size for getpw*_r(). */
+ size_t bufsize;
+ /** A map from usernames to entries. */
+ struct trie by_name;
+ /** A map from UIDs to entries. */
+ struct trie by_uid;
+};
- for (size_t i = 0; i < darray_length(users->entries); ++i) {
- struct passwd *entry = &users->entries[i];
- struct trie_leaf *leaf = trie_insert_str(&users->by_name, entry->pw_name);
- if (leaf) {
- if (!leaf->value) {
- leaf->value = entry;
- }
- } else {
- error = errno;
- goto fail_free;
- }
+struct bfs_users *bfs_users_new(void) {
+ struct bfs_users *users = malloc(sizeof(*users));
+ if (!users) {
+ return NULL;
+ }
- leaf = trie_insert_mem(&users->by_uid, &entry->pw_uid, sizeof(entry->pw_uid));
- if (leaf) {
- if (!leaf->value) {
- leaf->value = entry;
- }
- } else {
- error = errno;
- goto fail_free;
- }
+ long bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
+ if (bufsize > 0) {
+ users->bufsize = bufsize;
+ } else {
+ users->bufsize = 1024;
}
+ trie_init(&users->by_name);
+ trie_init(&users->by_uid);
return users;
+}
-fail_end:
- endpwent();
-fail_free:
- bfs_users_free(users);
- errno = error;
- return NULL;
+/** bfs_getent() callback for getpwnam_r(). */
+static void *bfs_getpwnam_impl(const void *key, void *ent, void *buf, size_t bufsize) {
+ struct passwd *result;
+ errno = getpwnam_r(key, ent, buf, bufsize, &result);
+ return result;
}
-const struct passwd *bfs_getpwnam(const struct bfs_users *users, const char *name) {
- const struct trie_leaf *leaf = trie_find_str(&users->by_name, name);
- if (leaf) {
- return leaf->value;
- } else {
+const struct passwd *bfs_getpwnam(struct bfs_users *users, const char *name) {
+ struct trie_leaf *leaf = trie_insert_str(&users->by_name, name);
+ if (!leaf) {
return NULL;
}
+
+ return bfs_getent(leaf, bfs_getpwnam_impl, name, sizeof(struct passwd), users->bufsize);
}
-const struct passwd *bfs_getpwuid(const struct bfs_users *users, uid_t uid) {
- const struct trie_leaf *leaf = trie_find_mem(&users->by_uid, &uid, sizeof(uid));
- if (leaf) {
- return leaf->value;
- } else {
+/** bfs_getent() callback for getpwuid_r(). */
+static void *bfs_getpwuid_impl(const void *key, void *ent, void *buf, size_t bufsize) {
+ struct passwd *result;
+ errno = getpwuid_r(*(const uid_t *)key, ent, buf, bufsize, &result);
+ return result;
+}
+
+const struct passwd *bfs_getpwuid(struct bfs_users *users, uid_t uid) {
+ struct trie_leaf *leaf = trie_insert_mem(&users->by_uid, &uid, sizeof(uid));
+ if (!leaf) {
return NULL;
}
+
+ return bfs_getent(leaf, bfs_getpwuid_impl, &uid, sizeof(struct passwd), users->bufsize);
}
void bfs_users_free(struct bfs_users *users) {
if (users) {
+ TRIE_FOR_EACH(&users->by_uid, leaf) {
+ if (leaf->value != MISSING) {
+ free(leaf->value);
+ }
+ }
trie_destroy(&users->by_uid);
- trie_destroy(&users->by_name);
- for (size_t i = 0; i < darray_length(users->entries); ++i) {
- struct passwd *entry = &users->entries[i];
- free(entry->pw_shell);
- free(entry->pw_dir);
- free(entry->pw_name);
+ TRIE_FOR_EACH(&users->by_name, leaf) {
+ if (leaf->value != MISSING) {
+ free(leaf->value);
+ }
}
- darray_free(users->entries);
+ trie_destroy(&users->by_name);
free(users);
}
}
struct bfs_groups {
- /** The array of group entries. */
- struct group *entries;
+ /** Initial buffer size for getgr*_r(). */
+ size_t bufsize;
/** A map from group names to entries. */
struct trie by_name;
/** A map from GIDs to entries. */
struct trie by_gid;
};
-/**
- * struct group::gr_mem isn't properly aligned on macOS, so do this to avoid
- * ASAN warnings.
- */
-static char *next_gr_mem(void **gr_mem) {
- char *mem;
- memcpy(&mem, *gr_mem, sizeof(mem));
- *gr_mem = (char *)*gr_mem + sizeof(mem);
- return mem;
-}
-
-struct bfs_groups *bfs_groups_parse(void) {
- int error;
-
+struct bfs_groups *bfs_groups_new(void) {
struct bfs_groups *groups = malloc(sizeof(*groups));
if (!groups) {
return NULL;
}
- groups->entries = NULL;
- trie_init(&groups->by_name);
- trie_init(&groups->by_gid);
-
- setgrent();
-
- while (true) {
- errno = 0;
- struct group *ent = getgrent();
- if (!ent) {
- if (errno) {
- error = errno;
- goto fail_end;
- } else {
- break;
- }
- }
-
- if (DARRAY_PUSH(&groups->entries, ent) != 0) {
- error = errno;
- goto fail_end;
- }
- ent = groups->entries + darray_length(groups->entries) - 1;
-
- void *members = ent->gr_mem;
- ent->gr_mem = NULL;
-
- ent->gr_name = strdup(ent->gr_name);
- if (!ent->gr_name) {
- error = errno;
- goto fail_end;
- }
-
- for (char *mem = next_gr_mem(&members); mem; mem = next_gr_mem(&members)) {
- char *dup = strdup(mem);
- if (!dup) {
- error = errno;
- goto fail_end;
- }
-
- if (DARRAY_PUSH(&ent->gr_mem, &dup) != 0) {
- error = errno;
- free(dup);
- goto fail_end;
- }
- }
- }
-
- endgrent();
-
- for (size_t i = 0; i < darray_length(groups->entries); ++i) {
- struct group *entry = &groups->entries[i];
- struct trie_leaf *leaf = trie_insert_str(&groups->by_name, entry->gr_name);
- if (leaf) {
- if (!leaf->value) {
- leaf->value = entry;
- }
- } else {
- error = errno;
- goto fail_free;
- }
-
- leaf = trie_insert_mem(&groups->by_gid, &entry->gr_gid, sizeof(entry->gr_gid));
- if (leaf) {
- if (!leaf->value) {
- leaf->value = entry;
- }
- } else {
- error = errno;
- goto fail_free;
- }
+ long bufsize = sysconf(_SC_GETGR_R_SIZE_MAX);
+ if (bufsize > 0) {
+ groups->bufsize = bufsize;
+ } else {
+ groups->bufsize = 1024;
}
+ trie_init(&groups->by_name);
+ trie_init(&groups->by_gid);
return groups;
+}
-fail_end:
- endgrent();
-fail_free:
- bfs_groups_free(groups);
- errno = error;
- return NULL;
+/** bfs_getent() callback for getgrnam_r(). */
+static void *bfs_getgrnam_impl(const void *key, void *ent, void *buf, size_t bufsize) {
+ struct group *result;
+ errno = getgrnam_r(key, ent, buf, bufsize, &result);
+ return result;
}
-const struct group *bfs_getgrnam(const struct bfs_groups *groups, const char *name) {
- const struct trie_leaf *leaf = trie_find_str(&groups->by_name, name);
- if (leaf) {
- return leaf->value;
- } else {
+const struct group *bfs_getgrnam(struct bfs_groups *groups, const char *name) {
+ struct trie_leaf *leaf = trie_insert_str(&groups->by_name, name);
+ if (!leaf) {
return NULL;
}
+
+ return bfs_getent(leaf, bfs_getgrnam_impl, name, sizeof(struct group), groups->bufsize);
}
-const struct group *bfs_getgrgid(const struct bfs_groups *groups, gid_t gid) {
- const struct trie_leaf *leaf = trie_find_mem(&groups->by_gid, &gid, sizeof(gid));
- if (leaf) {
- return leaf->value;
- } else {
+/** bfs_getent() callback for getgrgid_r(). */
+static void *bfs_getgrgid_impl(const void *key, void *ent, void *buf, size_t bufsize) {
+ struct group *result;
+ errno = getgrgid_r(*(const gid_t *)key, ent, buf, bufsize, &result);
+ return result;
+}
+
+const struct group *bfs_getgrgid(struct bfs_groups *groups, gid_t gid) {
+ struct trie_leaf *leaf = trie_insert_mem(&groups->by_gid, &gid, sizeof(gid));
+ if (!leaf) {
return NULL;
}
+
+ return bfs_getent(leaf, bfs_getgrgid_impl, &gid, sizeof(struct group), groups->bufsize);
}
void bfs_groups_free(struct bfs_groups *groups) {
if (groups) {
+ TRIE_FOR_EACH(&groups->by_gid, leaf) {
+ if (leaf->value != MISSING) {
+ free(leaf->value);
+ }
+ }
trie_destroy(&groups->by_gid);
- trie_destroy(&groups->by_name);
- for (size_t i = 0; i < darray_length(groups->entries); ++i) {
- struct group *entry = &groups->entries[i];
- for (size_t j = 0; j < darray_length(entry->gr_mem); ++j) {
- free(entry->gr_mem[j]);
+ TRIE_FOR_EACH(&groups->by_name, leaf) {
+ if (leaf->value != MISSING) {
+ free(leaf->value);
}
- darray_free(entry->gr_mem);
- free(entry->gr_name);
}
- darray_free(groups->entries);
+ trie_destroy(&groups->by_name);
free(groups);
}
diff --git a/src/pwcache.h b/src/pwcache.h
index f1a1db3..6ae8bea 100644
--- a/src/pwcache.h
+++ b/src/pwcache.h
@@ -25,92 +25,96 @@
#include <pwd.h>
/**
- * The user table.
+ * A user cache.
*/
struct bfs_users;
/**
- * Parse the user table.
+ * Create a user cache.
*
* @return
- * The parsed user table, or NULL on failure.
+ * A new user cache, or NULL on failure.
*/
-struct bfs_users *bfs_users_parse(void);
+struct bfs_users *bfs_users_new(void);
/**
* Get a user entry by name.
*
* @param users
- * The user table.
+ * The user cache.
* @param name
* The username to look up.
* @return
- * The matching user, or NULL if not found.
+ * The matching user, or NULL if not found (errno == 0) or an error
+ * occurred (errno != 0).
*/
-const struct passwd *bfs_getpwnam(const struct bfs_users *users, const char *name);
+const struct passwd *bfs_getpwnam(struct bfs_users *users, const char *name);
/**
* Get a user entry by ID.
*
* @param users
- * The user table.
+ * The user cache.
* @param uid
* The ID to look up.
* @return
- * The matching user, or NULL if not found.
+ * The matching user, or NULL if not found (errno == 0) or an error
+ * occurred (errno != 0).
*/
-const struct passwd *bfs_getpwuid(const struct bfs_users *users, uid_t uid);
+const struct passwd *bfs_getpwuid(struct bfs_users *users, uid_t uid);
/**
- * Free a user table.
+ * Free a user cache.
*
* @param users
- * The user table to free.
+ * The user cache to free.
*/
void bfs_users_free(struct bfs_users *users);
/**
- * The group table.
+ * A group cache.
*/
struct bfs_groups;
/**
- * Parse the group table.
+ * Create a group cache.
*
* @return
- * The parsed group table, or NULL on failure.
+ * A new group cache, or NULL on failure.
*/
-struct bfs_groups *bfs_groups_parse(void);
+struct bfs_groups *bfs_groups_new(void);
/**
* Get a group entry by name.
*
* @param groups
- * The group table.
+ * The group cache.
* @param name
* The group name to look up.
* @return
- * The matching group, or NULL if not found.
+ * The matching group, or NULL if not found (errno == 0) or an error
+ * occurred (errno != 0).
*/
-const struct group *bfs_getgrnam(const struct bfs_groups *groups, const char *name);
+const struct group *bfs_getgrnam(struct bfs_groups *groups, const char *name);
/**
* Get a group entry by ID.
*
* @param groups
- * The group table.
+ * The group cache.
* @param uid
* The ID to look up.
* @return
- * The matching group, or NULL if not found.
+ * The matching group, or NULL if not found (errno == 0) or an error
+ * occurred (errno != 0).
*/
-const struct group *bfs_getgrgid(const struct bfs_groups *groups, gid_t gid);
+const struct group *bfs_getgrgid(struct bfs_groups *groups, gid_t gid);
/**
- * Free a group table.
+ * Free a group cache.
*
* @param groups
- * The group table to free.
+ * The group cache to free.
*/
void bfs_groups_free(struct bfs_groups *groups);